White transit cop grabs his gun thinking its his Taser and shoots a black man dead. In the back. While he was on the ground.
DO NOT join the whitewash camp on the left in pretending that the kid had no part in the matter. Had all gone "by the book" he'd have still gotten himself GOOD and Tazed; probably multiple times.
No, things DIDN'T go "by the book"; they went tragically wrong, and Mehserle made a horrible, irreversible error.
But regardless of that error, it remains a fact for the annals of history, that the belligerent behavior of the deceased as he actively resisted arrest was a primary factor in his untimely, unintended demise.